Systems with integrated optically pumped vertical cavity surface emitting lasers

ABSTRACT

An integrated optically pumped vertical cavity surface emitting laser (VCSEL) is formed by integrating an electrically pumped in-plane semiconductor laser and a vertical cavity surface emitting laser together with a beam steering element formed with the in-plane semiconductor laser. The in-plane semiconductor laser can be a number of different types of in-plane lasers including an edge emitting laser, an in-plane surface emitting laser, or a folded cavity surface emitting laser. The in-plane semiconductor laser optically pumps the VCSEL to cause it to lase. The in-plane semiconductor laser is designed to emit photons of relatively short wavelengths while the VCSEL is designed to emit photons of relatively long wavelengths. The in-plane semiconductor laser and the VCSEL can be coupled together in a number of ways including atomic bonding, wafer bonding, metal bonding, epoxy glue or other well know semiconductor bonding techniques. The beam steering element can be an optical grating or a mirrored surface.

FIELD OF THE INVENTION

[0001] The present invention relates generally to semiconductor lasers.More particularly, the present invention relates to optically pumpedsemiconductor lasers.

BACKGROUND OF THE INVENTION

[0002] Semiconductor lasers have become more important. One of the mostimportant applications of semiconductor lasers is in communicationsystems where fiber optic communication media is employed. With growthin electronic communication, communication speed has become moreimportant in order to increase data bandwidth in electroniccommunication systems. Improved semiconductor lasers can play a vitalroll in increasing data bandwidth in communication systems using fiberoptic communication media such as local area networks (LANs),metropolitan area networks (MANs) and wide area networks (WANs). Apreferred component for optical interconnection of electronic componentsand systems via optical fibers is a semiconductor laser known as avertical cavity surface emitting laser (VCSEL). The current state ofdesign and operation of VCSELs is well known. Due to optical propertiesof optical fibers, photons emitted at longer wavelengths from a lasertend to propagate longer distances and are less disturbed by opticalnoise sources. Thus, forming a VCSEL that can operate at longerwavelengths, such as a wavelength greater than 1.25 μm, is desirable.

[0003] Lasers can be excited or pumped in a number of ways. Typically,VCSELs have been electrically excited (electrically pumped) by a powersupply in order to stimulate photon emission. However, achieving photonemission at long wavelengths using electrical pumping has not beencommercially successful due to a number of disadvantages. Presently,there is no viable monolithic electrically pumped long wavelength VCSELsolution for practical applications. It is desirable to use anIndium-Phosphide semiconductor substrate for long wavelength VCSELoperation. However, there is no monolithic semiconductor diffractiveBragg reflector (DBR) which can lattice match with an Indium-Phosphidesubstrate and provide a large enough difference in index of refractionfor reflecting a laser beam. Lattice matching is important in order tomaintain laser material growth dislocation-free. Alternatives have beenproposed and demonstrated with limited success. One solution is to waferbond an Indium-Phosphide based active material system with aGallium-Arsenide/Aluminum-Gallium-Arsenide (GaAs/AlGaAs) DBR. Whileconstant wave (CW) operation of up to 70 degrees centigrade has beenachieved, the output power is too low for the device to be of any use.

[0004] More recently it has been shown that a VCSEL can be opticallyexcited (optically pumped) to stimulate photon emission. Referring nowto FIG. 1, it has been shown that an in-plane laser 100 can have itsemitted photons 101A redirected by a mirror 102 into the direction ofphotons 101B for coupling into a VCSEL 106. The in-plane laser 100 isdesigned to be electrically excited in order to emit photons 101A atrelatively short wavelengths (850 nanometers (nm) to 980 nanometers(nm)). The redirected photons 101B from the in-plane laser 100, alsohaving relatively short wavelengths, optically excite the VCSEL 106. TheVCSEL 106 is designed to be optically excited in order to emit photons108 at relatively long wavelengths (1250 nm to 1800 nm). A disadvantageto the system of FIG. 1 is that its components are not integratedtogether. In U.S. Pat. Nos. 5,513,204 and 5,754,578 by VijaysekharJayaraman (referred to as the “Jayaraman Patents”) it is shown how tointegrate an electrically pumped short wavelength VCSEL together with anoptically pumped long wavelength VCSEL. However, there are a number ofdisadvantages to the integrated solution offered by the JayaramanPatents. One problem with using an electrically pumped short wavelengthVCSEL to optically pump a long wavelength VCSEL is that enormous heat isgenerated in the electrically pumped short wavelength VCSEL due toelectrical current injection. The heat generated by the electricallypumped VCSEL can not be dissipated efficiently which then is coupledinto the long wavelength VCSEL increasing its junction temperature suchthat it can not lase efficiently. Another disadvantage is that theelectrical resistivity is high because the electrical contact area inthe electrically pumped short wavelength VCSEL is relatively small, andthe current has to go through many layers of resistive p-type doped DBR.Another disadvantage in using an electrically pumped VCSEL is that thethermal resistance is high because of a restricted heat flow path. Thesmall carrier confinement region in an electrically pumped VCSEL causesheat to accumulate in a small area from which it is difficult todissipate. Another disadvantage is that the output power from anelectrically pumped short wavelength VCSEL is limited, which negativelyimpacts the output power from the optically pumped long wavelength VCSELas well. The integrated solution of the Jayaraman Patents can notprovide sufficient power to meet a data link module specification ofproviding a constant wave power output at eighty degrees Centigrade.Another disadvantage is that the cost of manufacturing the two VCSELs asproposed in the Jayaraman Patents is relatively high.

[0005] It is desirable to overcome the limitations of the prior art.

BRIEF SUMMARY OF THE INVENTION

[0006] Briefly, the present invention includes a method, apparatus andsystem as described in the claims. An integrated optically pumpedvertical cavity surface emitting laser (VCSEL) is formed by integratingan electrically pumped in-plane semiconductor laser and a verticalcavity surface emitting laser together with a beam steering elementformed with the in-plane semiconductor laser. The in-plane semiconductorlaser can be a number of different types of in-plane lasers including anedge emitting laser, an in-plane surface emitting laser, or a foldedcavity surface emitting laser. The in-plane semiconductor laseroptically pumps the VCSEL to cause it to lase. The in-planesemiconductor laser is designed to emit photons of relatively shortwavelengths while the VCSEL is designed to emit photons of relativelylong wavelengths. The in-plane semiconductor laser and the VCSEL can becoupled together in a number of ways including atomic bonding, waferbonding, metal bonding, epoxy glue or other well know semiconductorbonding techniques. The beam steering element can be an optical gratingor a mirrored surface. A number of embodiments of the integratedoptically pumped vertical cavity surface emitting laser are disclosed.

BRIEF DESCRIPTIONS OF THE DRAWINGS

[0007]FIG. 1 is a block diagram of a prior art system of opticallypumping a long-wavelength VCSEL.

[0008]FIG. 2 is a magnified cross sectional view of a first embodimentof the integrated optically pumped long wavelength VCSEL of the presentinvention.

[0009]FIGS. 3A through 3F are second through seventh embodiments of theintegrated optically pumped long wavelength VCSEL of the presentinvention.

[0010]FIGS. 4A and 4B are magnified cross sectional views of an eighthembodiment of the integrated optically pumped long wavelength VCSEL ofthe present invention.

[0011]FIGS. 5A and 5B are magnified cross sectional views of an array ofintegrated optically pumped long wavelength VCSELs for a ninthembodiment of the present invention.

[0012] Like reference numbers and designations in the drawings indicatelike elements providing similar functionality.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0013] In the following detailed description of the present invention,numerous specific details are set forth in order to provide a thoroughunderstanding of the present invention. However, it will be obvious toone skilled in the art that the present invention may be practicedwithout these specific details. In other instances well known methods,procedures, components, and circuits have not been described in detailso as not to unnecessarily obscure aspects of the present invention.

[0014] An integrated optically pumped vertical cavity surface emittinglaser (VCSEL) is formed by integrating an electrically pumped in-planesemiconductor laser and a vertical cavity surface emitting lasertogether with a beam steering element formed with the in-planesemiconductor laser. The in-plane semiconductor laser can be a number ofdifferent types of in-plane lasers including an edge emitting laser, anin-plane surface emitting laser, or a folded cavity surface emittinglaser. The in-plane semiconductor laser optically pumps the VCSEL tocause it to lase. The in-plane semiconductor laser is designed to emitphotons of relatively short wavelengths while the VCSEL is designed toemit photons of relatively long wavelengths. The in-plane semiconductorlaser and the VCSEL can be coupled together in a number of waysincluding atomic bonding, wafer bonding, metal bonding, epoxy glue orother well known semiconductor bonding techniques. The beam steeringelement can be an optical grating or a mirrored surface. A number ofembodiments of the integrated optically pumped vertical cavity surfaceemitting laser are disclosed.

[0015] The electrically pumped in-plane short wavelength semiconductorlaser is designed to operate at relatively short wavelengths (from 770nanometers (nm) to 1100 nanometers (nm)) with an optically pumped longwavelength VCSEL designed to operate at relatively long wavelengths(from 1250 nm to 1700 nm). The in-plane short wavelength semiconductorlaser of the integrated optically pumped VCSEL can be a conventionaledge emitting laser or an in-plane surface emitting laser. The longwavelength VCSEL operates without the use of electric power by beingoptically pumped by the short wavelength semiconductor laser which iselectrically pumped. Integration of the lasers depends upon the type ofsemiconductor materials utilized in forming the two lasers. The twolasers are integrated into one unit through semiconductor processingmethods such as monolithic epitaxial growth or by joining outer layersof the two lasers together through atomic bonding, wafer bonding, metalbonding, epoxy glue or other well known semiconductor bondingtechniques. Additionally, the vertical cavity surface emitting laser canbe bonded to the in-plane semiconductor laser at an angle in order toavoid reflected light from the long wavelength VCSEL being directlyreturned to the in-plane laser thereby avoiding optical noise being fedback to the in-plane laser. A third laser can also be used to generate asmall spot pump beam to couple to the vertical cavity surface emittinglaser in order to gain guide photons to emit at a single modetransversely. Although the in-plane short wavelength semiconductorlaser, also referred to as the pump laser, can be multimode eitherlongitudinally or transversely, the output from the long wavelengthVCSEL is single mode longitudinally. The output from the long wavelengthVCSEL can be single mode transversely depending upon the geometricintegration scheme and patterning. It is preferred that the longwavelength VCSEL operate in a single transverse mode to optimally couplewith a single mode fiber. Modulation of the long wavelength VCSEL can beachieved through either direct electrical modulation of the in-planeshort wavelength semiconductor laser or external modulation using anexternal modulator.

[0016] Referring now to FIG. 2, an integrated optically pumped VCSEL 200as a first embodiment of the present invention is illustrated. Theintegrated optically pumped VCSEL 200 includes a short wavelengthin-plane semiconductor laser, the edge-emitting laser 240, integratedwith a long wavelength VCSEL 250. The edge emitting (EE) laser 240 canemit a laser beam (i.e. photons) at a wavelength over a range from 600nm to 1110 nm. The edge emitting laser 240 will typically emit photonshaving wavelengths of 780 nm, 850 nm, or 980 nm. The laser beam 209A issteered by a beam steering element 212 towards the long wavelength VCSEL250 to optically pump it. In response to the optical pumping, the longwavelength VCSEL 250 emits a laser beam at a wavelength over a rangefrom 1250 nm to 1650 nm. The long wavelength VCSEL 250 typically emits alaser bean having a wavelength of 1300 nm or 1550 nm. The beam steeringelement 212 can be a mirror, an optical grating or other reflectingsurface. The beam steering element 212 in the preferred embodimentsteers photons at an angle substantially perpendicular with the beam209A to form laser beam 209B. In this case the incident and refractiveangles are substantially forty-five degrees.

[0017] The edge emitting laser 240 includes a substrate 201, a claddinglayer 202, an active area 203, and a cladding and contact layer 204. Thesubstrate 201 is preferably Gallium-Arsenide (GaAs) which may be removedafter the formation of the integrated optically pumped VCSEL structure200 is completed. The cladding 202 is preferably Gallium-Arsenide (GaAs)or Aluminum-Gallium-Arsenide (AlGaAs). The substrate 201 or claddinglayer 202 may act as the contact layer for making one of the electricalcontacts for the electrically pumped in-plane semiconductor laser. Theactive layer 203 has its materials selected depending upon the desiredwavelength of photons output. In the case that 980 nanometers (nm)wavelength is desired, active layer 203 is InGaAs quantum wells (QWs).In the case that 850 nm is desired, the active layer 203 isGallium-Arsenide (GaAs) QWs. In the case that the desired wavelength is780 nm, the active layer may be Gallium-Aluminum-Arsenide (GaAlAs) orGallium-Indium-Arsenide-Phosphide (GaInAsP) QWs. In the preferredembodiment the cladding and contact layer 204 is a P-type GaAs material.To stimulate emission, the straight facets 211A and 211B act as mirrorsfor the laser cavity. The facets 211A and 211B are parallel to eachother and formed by cleaving, etching, ion milling or other well knownsemiconductor process. A dielectric coating may be added to the facets211A and 211B to act as a mirror coating to increase the reflectivityefficiency. The photons emitted from the edge-emitting laser 240 arereflected or deflected by the beam steering element 212 into the longwavelength VCSEL 250. The beam steering element 212 is set an angle ofapproximately forty five degrees with the incident photons to reflectthem towards the long wavelength VCSEL 250. The beam steering element212 is formed by dry etching or ion milling processes or other wellknown semiconductor process for removing materials. The facets 211A and211B are coupled to the laser cavity of the in-plane semiconductor laserwhile the beam steering element 212 is formed exterior to the cavity butintegrated with the integrated optically pumped VCSEL 200. The longwavelength VCSEL 250 is comprised of a Diffractive Bragg Reflector (DBR)205, a long wavelength active area 206, a second Diffractive BraggReflector (DBR) 207 and a substrate 208. The diffractive Bragg ReflectorDBR 205 is specifically designed for the desired long wavelength byforming the pairs of materials with a quarter wavelength in thicknessfor each layer. The DBR 205 may be a dielectric DBR, a GaAs/AlGaAs DBR,an InP/InGaAsP DBR, or an InP/InAlGaAs DBR. The dielectric DBR is formedby depositing silicon dioxide/titanium dioxide pairs of quarterwavelength thickness layers or other equivalent material layers. Theactive area 206 for the long wavelength VCSEL may be a single quantumwell or a multiple number of quantum wells formed from materials such asInGaAsP or InAlGaAs. In the preferred embodiment, the active area 206has 3 to 9 quantum wells formed of InGaAsP. DBR 207 is formed similarlyto the DBR 205 for long wavelength VCSEL operation. Substrate 208, uponwhich the long wavelength VCSEL 250 has been formed, is preferably anInP substrate or a GaAs substrate which may be removed after theintegrated optically pumped VCSEL structure is completed after bondingtogether. The edge-emitting laser 240 may include a ridge-wave guide, arib-wave guide, an oxide-confined or other well-known lasing enhancementstructure. The long wavelength VCSEL 250 may be gain guided by pumping,index guided by oxide, or index guided by etching mesas. In operation,laser beam 209A is reflected back and forth between facets 211A and 211Bbefore being emitted by the edge-emitting laser 240 as the shortwavelength laser output. Laser beam 209A is steered by the beam steeringelement 212 substantial perpendicular in the direction of laser beam209B. Laser beam 209B is coupled into the long wavelength VCSEL 250 tooptically pump it into generating the laser beam 222 at longwavelengths.

[0018] In-plane semiconductor lasers such as edge-emitting lasers arerelatively easy to manufacture with a relatively high power output.Edge-emitting lasers have the advantage of spreading out the heatgenerated by the active area 203 such that its thermal resistance islower. Additionally, the edge-emitting laser has a larger surface areafor making electrical contacts such that the electrical resistance isalso reduced. Because the electrically pumped in-plane semiconductorlasers, including edge-emitting laser 240, can generate sufficientlyhigh power there is no need to coat the beam steering elements toimprove the reflection efficiency into the long wavelength VCSEL 250. Inthe first embodiment of the integrated optically pumped VCSEL of FIG. 2,the edge emitting laser 240 is bonded to the long wavelength VCSEL 250at either the bonding interface 210A or 210B depending upon whether theDBR 205 of the VCSEL 250 is grown with the edge emitting laser 240. IfDBR 205 is made of pairs of GaAs/AlGaAs materials it is grown with theedge emitting laser 240 and the bonding interface between the lasers is210B. If the DBR 205 is not made of pairs of GaAs/AlGaAs materials butof some other material such as a dielectric DBR, InP/InGaAsP DBR, orInP/InAlGaAsP DBR, then the bonding interface between the lasers is210A. The two lasers are bonded together at either bonding interface210A or 210B through atomic bonding, molecular bonding, metal bonding,epoxy bonding, or other well-known bonding methods for bondingsemiconductor materials. The material used to bond at the bondinginterface 210A or 210B is optically transparent for transmission ofphotons at the desired wavelength.

[0019] Referring now to FIGS. 3A through 3F, integrated optically pumpedVCSELs 300A through 300F are illustrated. In FIG. 3A, the integratedoptically pumped VCSEL 300A comprises an in-plane semiconductor laser,an in-plane surface emitting laser 340A, and a long wavelength VCSEL350A. The in-plane surface emitting laser 340A is coupled to the longwavelength VCSEL 350A at either the bonding interface 310A or bondinginterface 310B depending upon whether the DBR 303 of the VCSEL 350A isgrown with the in-plane surface emitting laser 340A or not. If DBR 303is made of pairs of GaAs/AlGaAs materials it is grown with the in-planesurface emitting laser 340A and the bonding interface between the lasersis 310B. If the DBR 303 is not made of pairs of GaAs/AlGaAs materialsbut of some other material such as a dielectric DBR, InP/InGaAsP DBR, orInP/InAlGaAsP DBR which is grown with the VCSEL 350A, then the bondinginterface between the lasers is 310A. The in-plane surface emittinglaser 340A may be bonded to the long wavelength VCSEL 350A by means ofwafer bonding, metal bonding, epoxy bonding, or other well-knownsemiconductor bonding techniques. The in-plane surface emitting laser340A is composed of multiple layers of well-known materials similar toin-plane laser 240 in FIG. 2. The in-plane laser can include confinementstructures including an etched mesa, rib or oxide carrier confinementstructure forming a ridge waveguide in-plane semiconductor laser, a ribwaveguide in-plane semiconductor laser, or an oxide confined in-planesemiconductor laser respectively. The in-plane surface emitting laser340A includes a laser cavity mirror 302 coupled to a cladding layer toreflect photons within the laser cavity and allow photons of sufficientenergy to pass through. In-plane surface emitting laser 340A ispreferably manufactured and designed to lase at 780 nm, 850 nm, or 980nm. The substrate of the in-plane surface emitting laser is preferablyGallium-Arsenide (GaAs), which is optionally removed from the integratedoptically-pumped VCSEL 300A. In contrast with the beam steering element212 being outside the laser cavity, the in-plane surface emitting laser340A includes the beam steering element 312 in the laser cavity of thein-plane surface emitting laser 340A for reflection. The beam steeringelement 312 is preferably at an angle of substantially forty fivedegrees and is formed by etching the semiconductor materials of thein-plane surface emitting laser 340A. The straight facet 311 is formedby cleaving or etching substantially perpendicular with thesemiconductor materials of the laser 340A. The beam steering element 312within the laser cavity provides a total reflection to the incominglight from either the in-plane laser cavity facet 311 or from the lasercavity mirror 302. The laser cavity mirror 302 is formed similarly to aDBR and includes layers of the pair of materialsAl_(x)Ga_(1-x)As/Al_(y)Ga_(1-y)As to reflect and transmit the shortwavelength photons.

[0020] The laser cavity mirror 302 and the beam steering element 312 canbe substituted for a grating surface forming an in-plane grating surfaceemitting laser. The grating surface can have its ridges formed (spacing,etching angles, etc.) such that it can act both as a mirror surface toreflect photons in the laser cavity and to steer short wavelengthphotons into the long wavelength VCSEL 350A. The long wavelength VCSEL350A comprises a diffractive Bragg reflector (DBR) 303, active area 304,a second DBR 305, and a substrate 306. The short wavelength photonsgenerated by the in-plane surface emitting laser 340A are preferably ofwavelengths 780 nm, 850 nm, or 980 nm. DBR 303 and DBR 305 are designedspecifically for the long wavelength VCSEL 350A and can be a dielectricDBR, an Al_(x)Ga_(1-x)As/Al_(y)Ga_(1-y)As DBR, or a InP/InGaAsP DBR. Theactive area 304 is specifically designed for long wavelength VCSELs andmay be a single or multiple quantum well structure formed fromIndium-Gallium-Arsenide-Phosphide (InGaAsP), Indium-Gallium-Arsenide(InGaAs), Indium-Aluminum-Gallium-Arsenide (InAlGaAs),Gallium-Arsenide-Antimonide (GaAsSb), or Indium-Gallium-Arsenide-Nitride(InGaAsN). Substrate 306, depending on the other materials used informing the VCSEL laser 350A, is an InP or a GaAs substrate. In theoperation of the integrated optically pumped VCSEL 300A, the photons309A at short wavelengths are reflected between by the straight facet311, the beam steering element 312 and the laser cavity mirror 302 ofthe in-plane surface emitting laser 340A. The laser beam 309B of shortwavelength photons output from the in-plane surface emitting laser 340Aare coupled into the long wavelength VCSEL 350A to optically pump it.Upon reaching the lasing threshold, the long wavelength VCSEL 350A emitsthe long wavelength photons 333.

[0021] Referring now to FIG. 3B, the integrated long wavelengthoptically pumped VCSEL 300B having the in-plane surface emitting laser340B and the long wavelength VCSEL 350B is illustrated. The integratedoptically pumped VCSEL 300B is similar to the integrated opticallypumped VCSEL 300A but has two beam steering elements 312A and 312Bformed in the cavity of the in-plane surface emitting laser 340B. Thebeam steering element 312B is preferable over the straight edged facet311 in that it is simpler to manufacture and provides a more efficientreflective surface which provides a higher output power. The beamsteering element 312B is similar to the beam steering element 312A. Toavoid two laser beams being emitted from two locations of the surface ofthe VCSEL, a portion 313 of the DBR mirror 303 is removed where thelaser beam would otherwise be reflected to eliminate one of the longwavelength VCSEL resonant cavity mirrors. Portion 313 is removedpreferably by etching but other well known semiconductor processingtechniques may be used such as ion milling. The other elements of thein-plane surface emitting laser 340B and the long wavelength VCSEL 350Bare similar to lasers 340A and 350A previously described with respect tothe integrated long wavelength VCSEL 300A of FIG. 3A.

[0022] Referring now to FIG. 3C, the integrated long wavelengthoptically pumped VCSEL 300C with in-plane surface emitting laser 340Band long wavelength VCSEL 350C is illustrated. Integrated opticallypumped VCSEL 300C has the same in-plane surface emitting laser 340B asdoes VCSEL 300B with the beam steering elements 312A and 312B. In thelong wavelength VCSEL 350C, instead of portion 313 being removed fromlayer 303, portion 314 is removed from the active area 304 in order forthe single laser beam 333 to be emitted from the surface of the longwavelength VCSEL 350C. Otherwise, similarly numbered elements of thein-plane surface emitting laser 340B and the VCSEL 350C are similar tothose previously described with respect to FIG. 3B and the integratedoptically pumped VCSEL 300B.

[0023] Referring now to FIG. 3D, a fifth embodiment, integratedoptically pumped VCSEL 300D is illustrated. The integrated opticallypumped VCSEL 300D includes the in-plane surface emitting laser 340B andthe long wavelength VCSEL 350D. Integrated optically pumped VCSEL 300Dhas the same in-plane surface emitting laser 340B as does VCSEL 300Bwith the beam steering elements 312A and 312B. Instead of portion 313 or314, the long wavelength VCSEL 350D has portion 315 removed from thematerial of the Diffractive Bragg Reflector (DBR) 305 and the substrate306. This causes a single laser beam 333 to be emitted from the surfaceof the long wavelength VCSEL 350D. Otherwise, similarly numberedelements of the in-plane surface emitting laser 340B and the VCSEL 350Dare similar to those previously described with respect to FIG. 3B andthe integrated optically pumped VCSEL 300B.

[0024] Referring now to FIG. 3E, the integrated optically pumped VCSEL300E is illustrated. The integrated optically pumped VCSEL 300E includesthe in-plane surface emitting laser 340B and the long wavelength VCSEL350E. Integrated optically pumped VCSEL 300E has the same in-planesurface emitting laser 340B as does VCSEL 300B with the beam steeringelements 312A and 312B. Instead of portions 313, 314, or 315, the longwavelength VCSEL 350E now has a portion 316 removed from the DiffractiveBragg Reflector DBR 303, the active area 304, DBR 305, and the substrate306. In this manner a single laser beam 333 is emitted from the longwavelength VCSEL 350E. Otherwise, similarly numbered elements of thein-plane surface emitting laser 340B and the VCSEL 350E are similar tothose previously described with respect to FIG. 3B and the integratedoptically pumped VCSEL 300B.

[0025] Referring now to FIG. 3F, a seventh embodiment of the integratedoptically pumped VCSEL 300F is illustrated. The integrated opticallypumped VCSEL 300F includes the in-plane surface emitting laser 340C andthe long wavelength VCSEL 350F. The in-plane surface emitting laser 340Cincludes its own substrate 301 and the beam steering elements 312A and312B. The long wavelength VCSEL 350F has its substrate 306 removed andinstead of portions 313, 314, 315, or 316, a portion 317 is removed fromthe Diffractive Bragg Reflector DBR 303, active area 304, and DBR 305.FIG. 3F illustrates how either one of the substrate for the in-planesurface emitting laser 340 or the substrate for the long wavelengthVCSEL 350 can be removed.

[0026] Referring now to FIG. 4A, the integrated optically pumped VCSEL400 is illustrated. The integrated optically pumped VCSEL 400 includes afolded cavity surface emitting laser (FCSEL) 440 integrated with a longwavelength VCSEL 450. The folding cavity surface emitting laser 440includes an n-type doped GaAs substrate 401, a Diffractive BraggReflector DBR 402, an active area 404, and a cladding layer 406. Thesubstrate 401 is preferably GaAs. The layers of the DBR 402 arepreferably formed from n-type Al_(x)Ga_(1-x)As/Al_(y)Ga_(1-y)As pairs ofmaterial with x ranging from 0 and 0.5, and y ranging from 0.5 and 1,and has five to twenty five pairs normally and ten pairs of layers inthe preferred embodiment. The active area 404 can be GaAs, AlGaAs, orInGaAs quantum well structure and is preferably an InGaAs quantum wellstructure which can be a single quantum well or multiple quantum wellsbut in the preferred embodiment three to nine quantum wells areutilized. The cladding layer 406 is a p-type GaAs or AlGaAs and ispreferably a p-type GaAs. The active area 404, the cladding 406, and aportion 403 of the DBR 402 have an external-angled beam steering element412 and an internal-angled beam steering element 411 etched in theirmaterials. Preferably the external-angled beam steering element 412 andthe internal-angled beam steering element 411 are approximately fortyfive degree angles with the incident light and form the folded cavity ofthe folded cavity surface emitting laser 440. The long wavelength VCSEL450 includes the DBR 412, a quantum well active area 414, a DBR 416, anda substrate 418. The DBR 412 can be GaAs/AlGaAs DBR, InP/InGaAsP DBR, ordielectric DBR, and is preferably a dielectric DBR. The active area 414can be InGaAsP or InAlGaAs and is preferably an InGaAsP quantum wellstructure having multiple quantum wells. The DBR 416 can be GaAs/AlGaAsDBR, InGaAsP/InP or dielectric DBR, and is preferably made of pairs ofInGaAsP/InP. The substrate 418 of the long wavelength VCSEL 450 can beGaAs or InP, and is preferably an InP substrate. DBRs 412 and 416 arepreferably made of thicknesses to provide substantial (preferably 99% ormore) reflection of long wavelengths at 1.3 μm or 1.55 μm to amplify andstimulate emission. The folded cavity surface emitting laser 440 and thelong wavelength VCSEL 450 are integrated together at the interface 410by either fusing, gluing, metal bonding, epoxy bonding or otherwell-known semiconductor bonding method. The interface 410 canalternately be an air gap in the case where the FCSEL 440 and the longwavelength VCSEL 450 are held mechanically aligned together. Inoperation, the folded cavity surface emitting laser 440 generates ashort wavelength laser beam which is reflected between the beam steeringelement 411, beam steering element 412, DBR 402, and the top surface ofcladding 406 as 409A, 409B and 409C. The in-plane laser beam 409A isreflected by beam steering element 411 into the substantiallyperpendicular beam 409B for coupling into the long wavelength VCSEL 450to optically pump it. After becoming sufficiently pumped to reach lasingthreshold, the long wavelength VCSEL 450 emits the long wavelength laserbeam 444.

[0027] Referring now to FIG. 4B, a side cross-sectional view of theintegrated optically pumped vertical cavity surface emitting laser 400is illustrated. It can be seen in FIG. 4B that the cladding layer 406includes an oxide ridge 405 which provides confinement in currentinjection for the FCSEL 440. The oxide ridge 405 is formed by oxidizinga portion of an Aluminum-Arsenide (AlAs) layer or anAluminum-Gallium-Arsenide (AlGaAs) layer with very high Aluminum contentinto an Aluminum-Oxide (AlO₂) region.

[0028] Referring now to FIGS. 5A and 5B, an integrated array ofoptically pumped long wavelength VCSELs 500 is illustrated. Essentially,integrated array 500 includes N integrated optically pumped VCSELs 400.In FIG. 5B, integrated VCSEL 400A through integrated VCSEL 400N areformed on the base layers of the substrate 401 and DBR 402. Each of theintegrated VCSELs 400A through 400N are formed of separate folded cavitysurface emitting lasers FCSELs 440A through 440N integrated with thelong wavelength VCSELs 450A through 450N respectively. With each of thefolded cavity surface emitting lasers 440A through 440N having oneseparate electrical contact, each of the integrated long wavelengthVCSELs 400A through 400N can be individually controlled within theintegrated array 500. Each of the integrated VCSELs 400A through 400Nemits a separately controlled laser output 444A through 444N. Referringnow to FIG. 5A, the cross-section of the integrated VCSEL 400Aillustrates each instance of integrated optically pumped VCSELs 400Athrough 400N within the array. The folded vertical cavity surfaceemitting laser 440A includes the substrate 401, DBR 402, a section ofthe DBR 403A and active area 404A, a cladding layer 406A. The verticallong wavelength vertical cavity surface emitting laser 450A includes adielectric DBR 412A and active area 414A, a DBR 416A and a substrate418A. Each of the long wavelength vertical cavity surface lasers 450Athrough 450N couple to the respective folded cavity surface emittinglaser 440A through 440N by means of the interface 410A through 410N.Each of the FCSELs 440A through 440N share the same substrate 401 andDBR 402. The materials used in FCSELs 440A through 440N and longwavelength VCSELs 450A through 450N are the same as those described withrespect to the similarly numbered elements of the folded cavity surfaceemitting laser 440 and the long wavelength VCSEL 450 previouslydescribed with respect to FIGS. 4A and 4B of the integrated opticallypumped VCSEL 400. After integration of a large long wavelength VCSELwith a large FCSEL, all layers can be etched in the area between thelong wavelength VCSELs 450A through 450N and some layers can be etchedaway in the area between the FCSELs 440A through 440N in order to formthe array 500 of separately controlled integrated optically pumpedVCSELs.

[0029] Each embodiment of the integrated optically pumped VCSEL provideswavelength conversion from a short wavelength laser beam to a longwavelength laser beam output. Each embodiment of the integratedoptically pumped VCSEL can provide longitudinal mode conversion as well.Longitudinal mode is the spectral distribution of a laser beam asopposed to the transverse mode which effectively is the laser spatialmode. That is, with respect to the transverse mode, a multimode laserbeam can be converted into a single mode laser beam output or a singlemode laser beam can be converted into a multimode laser beam output.Alternatively no mode conversion need occur, such that, a shortwavelength multimode laser beam is generated as a long wavelengthmultimode laser beam output and a short wavelength single mode laserbeam is generated as a long wavelength single mode laser beam output.Whether a laser is single mode or multimode is determined by theimplementation of the pump laser, that is the in-plane short wavelengthlaser, and the geometric layout of the long wavelength VCSEL.

[0030] The present invention has many advantages over the prior art. Oneadvantage of the present invention is that it costs less to manufacturebecause it uses an in-plane short wavelength laser. Another advantage ofthe present invention is that it is less sensitive to temperaturevariance because it provides better heat dissipation through lowerthermal and electrical resistivity. Another advantage of the presentinvention is that it is an integrated solution that can undergo wafertesting to determine faulty devices and known good dies. Otheradvantages of the present invention will become obvious to those ofordinary skill in the art after thoroughly reading this disclosure.

[0031] The preferred embodiments of the present invention are thusdescribed. While the present invention has been described in particularembodiments, the present invention should not be construed as limited bysuch embodiments, but rather construed according to the claims thatfollow below.

What is claimed is:
 1. An integrated optically pumped vertical cavitysurface emitting laser comprising: an in-plane semiconductor laser toemit photons of a relatively short wavelength, the in-planesemiconductor laser being electrically pumped to generate the photons ofthe relatively short wavelength; a beam steering element coupled to thein-plane semiconductor laser, the beam steering element to steer thephotons of the relatively short wavelength emitted at an incident anglefrom the in-plane semiconductor laser into a reflective angle; and avertical cavity surface emitting laser coupled to the in-planesemiconductor laser, the vertical cavity surface emitting laser toreceive the photons of the relatively short wavelength emitted from thein-plane semiconductor laser and steered by the beam steering element tobe optically pumped and emit photons of a long wavelength from asurface.
 2. The integrated optically pumped vertical cavity surfaceemitting laser of claim 1 wherein, the in-plane semiconductor laser isan edge emitting laser.
 3. The integrated optically pumped verticalcavity surface emitting laser of claim 1 wherein, the in-planesemiconductor laser is an in-plane surface emitting laser.
 4. Theintegrated optically pumped vertical cavity surface emitting laser ofclaim 1 wherein, the in-plane semiconductor laser is a grating surfaceemitting laser.
 5. The integrated optically pumped vertical cavitysurface emitting laser of claim 1 wherein, the in-plane semiconductorlaser is a folded cavity surface emitting laser.
 6. The integratedoptically pumped vertical cavity surface emitting laser of claim 5wherein, the folded cavity surface emitting laser includes, an n-typeGallium-Arsenide substrate, an n-type Aluminum-Gallium-Arsenidediffractive Bragg reflector coupled to the substrate, an active regionhaving one or more Indium-Gallium-Arsenide quantum well structures, ap-type Gallium-Arsenide cladding layer coupled to the active region, anoxide confinement region formed within the cladding layer, and, wherein,the beam steering element is an internal-angled beam steering elementand an external-angled beam steering element formed in the edges of aportion of the n-type Aluminum-Gallium-Arsenide diffractive Braggreflector, the active region, and the cladding layer to steer photonstowards the vertical cavity surface emitting laser.
 7. The integratedoptically pumped vertical cavity surface emitting laser of claim 6wherein, the vertical cavity surface emitting laser includes, a firstdiffractive Bragg reflector formed of a dielectric material, an activeregion having one or more Indium-Gallium-Arsenide-Phosphide quantum wellstructures, a second diffractive Bragg reflector formed of layers of thepair of materials of Indium-Gallium-Arsenide-Phoside/Indium-Phosphide,and an Indium-Phosphide substrate coupled to the second diffractiveBragg reflector.
 8. The integrated optically pumped vertical cavitysurface emitting laser of claim 1 wherein, the in-plane semiconductorlaser is electrically pumped to emit photons having a wavelength rangingfrom 600 nanometers to 1100 nanometers.
 9. The integrated opticallypumped vertical cavity surface emitting laser of claim 1 wherein, thevertical cavity surface emitting laser is optically pumped to emitphotons having a wavelength ranging from 1200 nanometers to 1750nanometers.
 10. The integrated optically pumped vertical cavity surfaceemitting laser of claim 1 wherein, the vertical cavity surface emittinglaser is coupled to the in-plane semiconductor laser through one of theset of atomic bonding, wafer bonding, metal bonding, and epoxy bonding.11. The integrated optically pumped vertical cavity surface emittinglaser of claim 1 wherein, the in-plane semiconductor laser includes aridge waveguide forming a ridge waveguide in-plane semiconductor laser.12. The integrated optically pumped vertical cavity surface emittinglaser of claim 1 wherein, the in-plane semiconductor laser includes arib waveguide forming a rib waveguide in-plane semiconductor laser. 13.The integrated optically pumped vertical cavity surface emitting laserof claim 1 wherein, the in-plane semiconductor laser includes an oxideconfinement region forming an oxide confined in-plane semiconductorlaser.
 14. The integrated optically pumped vertical cavity surfaceemitting laser of claim 1 wherein, the in-plane semiconductor laser isan in-plane laser having an Aluminum free active region.
 15. Theintegrated optically pumped vertical cavity surface emitting laser ofclaim 1 wherein, the in-plane semiconductor laser includes a lasercavity mirror that is a naturally cleaved facet.
 16. The integratedoptically pumped vertical cavity surface emitting laser of claim 1wherein, the in-plane semiconductor laser includes a laser cavity mirrorthat is an etched facet.
 17. The integrated optically pumped verticalcavity surface emitting laser of claim 1 wherein, the beam steeringelement is also a laser cavity mirror formed by etching a facet at anangle to amplify the energy of the photons in the laser cavity and tosteer photons to the vertical cavity surface emitting laser.
 18. Theintegrated optically pumped vertical cavity surface emitting laser ofclaim 17 wherein, the angle that the facet is etched is in the rangefrom thirty-five degrees to fifty-five degrees.
 19. The integratedoptically pumped vertical cavity surface emitting laser of claim 1wherein, the angle that the facet is etched is in the range fromforty-two degrees to forty-eight degrees.
 20. The integrated opticallypumped vertical cavity surface emitting laser of claim 3 wherein, thein-plane surface emitting laser includes a cladding layer and asemiconductor diffractive Bragg reflector monolithically grown on thecladding layer to reflect and confine photons.
 21. The integratedoptically pumped vertical cavity surface emitting laser of claim 1wherein, the vertical cavity surface emitting laser is a long wavelengthvertical cavity surface emitting laser having an active region formed ofone or more Indium-Gallium-Arsenide-Phosphide quantum wells to beoptically pumped and emit photons of a relatively long wavelength. 22.The integrated optically pumped vertical cavity surface emitting laserof claim 1 wherein, the vertical cavity surface emitting laser is a longwavelength vertical cavity surface emitting laser having an activeregion formed of one or more Indium-Aluminum-Gallium-Arsenide quantumwells to be optically pumped and emit photons of a relatively longwavelength.
 23. The integrated optically pumped vertical cavity surfaceemitting laser of claim 1 wherein, the vertical cavity surface emittinglaser is a long wavelength vertical cavity surface emitting laser havingan active region formed of one or more Gallium-Arsenide-Antimonidequantum wells to be optically pumped and emit photons of a relativelylong wavelength.
 24. The integrated optically pumped vertical cavitysurface emitting laser of claim 1 wherein, the vertical cavity surfaceemitting laser is a long wavelength vertical cavity surface emittinglaser having an active region formed of one or moreIndium-Gallium-Arsenide-Nitride quantum wells to be optically pumped andemit photons of a relatively long wavelength.
 25. The integratedoptically pumped vertical cavity surface emitting laser of claim 1wherein, the vertical cavity surface emitting laser includes a firstdiffractive Bragg reflector mirror formed of Aluminum-Gallium-Arsenidemonolithically grown on a top layer of the in-plane semiconductor laserduring its semiconductor manufacturing.
 26. The integrated opticallypumped vertical cavity surface emitting laser of claim 25 wherein, allother layers of the vertical cavity surface emitting laser are processedseparately from the in-plane semiconductor laser, including an activeregion formed of one or more Indium-Gallium-Arsenide-Phosphide quantumwells, and are coupled to the first diffractive Bragg reflector mirrorgrown on the in-plane semiconductor laser through wafer fusing.
 27. Theintegrated optically pumped vertical cavity surface emitting laser ofclaim 25 wherein, all other layers of the vertical cavity surfaceemitting laser are processed separately from the in-plane semiconductorlaser, including an active region formed of one or moreIndium-Aluminum-Gallium-Arsenide quantum wells, and are coupled to thefirst diffractive Bragg reflector mirror grown on the in-planesemiconductor laser through wafer fusing.
 28. The integrated opticallypumped vertical cavity surface emitting laser of claim 25 wherein, allother layers of the vertical cavity surface emitting laser aremonolithically grown on top of the first diffractive Bragg reflectormirror during semiconductor processing of the in-plane semiconductorlaser including an active region formed of one or moreGallium-Arsenide-Antimonide quantum wells.
 29. The integrated opticallypumped vertical cavity surface emitting laser of claim 25 wherein, allother layers of the vertical cavity surface emitting laser aremonolithically grown on top of the first diffractive Bragg reflectormirror during semiconductor processing of the in-plane semiconductorlaser including an active region formed of one or moreIndium-Gallium-Arsenide-Nitride quantum wells.
 30. The integratedoptically pumped vertical cavity surface emitting laser of claim 1wherein, the vertical cavity surface emitting laser includes an activeregion of one or more quantum wells, a first diffractive Bragg reflectorand a second diffractive Bragg reflector, the second diffractive Braggreflector monolithically grown with the active region.
 31. Theintegrated optically pumped vertical cavity surface emitting laser ofclaim 1 wherein, the vertical cavity surface emitting laser includes anactive region of one or more quantum wells, a first diffractive Braggreflector, and a second diffractive Bragg reflector, the seconddiffractive Bragg reflector wafer fused to the active region.
 32. Theintegrated optically pumped vertical cavity surface emitting laser ofclaim 1 wherein, the vertical cavity surface emitting laser includes anactive region of one or more quantum wells, a first diffractive Braggreflector, and a second diffractive Bragg reflector, the seconddiffractive Bragg reflector metal bonded to the active region.
 33. Theintegrated optically pumped vertical cavity surface emitting laser ofclaim 1 wherein, the vertical cavity surface emitting laser includes anactive region of one or more quantum wells, a first diffractive Braggreflector, and a second diffractive Bragg reflector, the seconddiffractive Bragg reflector epoxy bonded to the active region.
 34. Theintegrated optically pumped vertical cavity surface emitting laser ofclaim 1 wherein, the vertical cavity surface emitting laser is bonded tothe in-plane semiconductor laser at an angle.
 35. The integratedoptically pumped vertical cavity surface emitting laser of claim 1wherein, the vertical cavity surface emitting laser includes an activeregion of one or more quantum wells and a dielectric mirror deposited ontop of the active region.
 36. The integrated optically pumped verticalcavity surface emitting laser of claim 1 wherein, the vertical cavitysurface emitting laser includes a dielectric mirror as its firstdiffractive Bragg reflector.
 37. The integrated optically pumpedvertical cavity surface emitting laser of claim 1 wherein, the verticalcavity surface emitting laser includes an oxide region in a first orsecond diffractive Bragg reflector to gain guide photons to emit at asingle mode transversely.
 38. The integrated optically pumped verticalcavity surface emitting laser of claim 1 wherein, the vertical cavitysurface emitting laser includes one or more mesa regions patterned in afirst or second diffractive Bragg reflector to index guide photons toemit at a single mode transversely.
 39. The integrated optically pumpedvertical cavity surface emitting laser of claim 1 further comprising: athird laser to generate a small spot pump beam to coupled to thevertical cavity surface emitting laser to gain guide photons to emit ata single mode transversely.
 40. The integrated optically pumped verticalcavity surface emitting laser of claim 1 wherein, the vertical cavitysurface emitting laser includes a patterned dielectric mirror coupled toits active region to emit photons at a single mode transversely.
 41. Theintegrated optically pumped vertical cavity surface emitting laser ofclaim 1 wherein, the beam steering element is integrated with thein-plane semiconductor laser.
 42. The integrated optically pumpedvertical cavity surface emitting laser of claim 41 wherein: the beamsteering element is a grating.
 43. The integrated optically pumpedvertical cavity surface emitting laser of claim 41 wherein: the beamsteering element is an angle etched facet.
 44. The integrated opticallypumped vertical cavity surface emitting laser of claim 43 wherein: theangle etched facet is integrated with the in-plane semiconductor laseras part of a laser cavity.
 45. The integrated optically pumped verticalcavity surface emitting laser of claim 43 wherein: the angle etchedfacet is integrated with the in-plane semiconductor laser external to alaser cavity.
 46. The integrated optically pumped vertical cavitysurface emitting laser of claim 42 wherein: the grating is integratedwith the in-plane semiconductor laser as part of the laser cavity. 47.The integrated optically pumped vertical cavity surface emitting laserof claim 42 wherein: the grating is integrated with the in-planesemiconductor laser external to the laser cavity.
 48. A semiconductorlaser apparatus comprising: a first semiconductor laser and a secondsemiconductor laser integrated with the first semiconductor laser; saidfirst semiconductor laser having a lasing action substantially in aplane of a semiconductor epitaxial plane to generate a first laser beam,said first semiconductor laser being responsive to electrical pumping;said second laser having a lasing action substantially perpendicular tothe semiconductor epitaxial plane to generate a second laser beam, saidsecond semiconductor laser being responsive to optical pumping by thefirst semiconductor laser; and a beam steering element to steer saidfirst laser beam in a direction towards said second laser.
 49. A methodof optically pumping a long wavelength vertical cavity surface emittinglaser, the method comprising: integrating a beam steering element withan in-plane semiconductor laser, integrating a vertical cavity surfaceemitting laser to the in-plane semiconductor laser, electrically pumpingthe in-plane semiconductor laser to generate a first plurality ofphotons to be steered by the beam steering element towards the verticalcavity surface emitting laser, receiving the first plurality of photonsin the vertical cavity surface emitting laser to generate a secondplurality of photons responsive to the receiving of the first pluralityof photons.
 50. The method of claim 49 wherein, the in-planesemiconductor laser is an edge emitting laser.
 51. The method of claim50 wherein, the beam steering element is external to the edge emittinglaser and couples to a substrate of the edge emitting laser.
 52. Themethod of claim 49 wherein, the in-plane semiconductor laser is anin-plane surface emitting laser.
 53. The method of claim 52 wherein, thebeam steering element is formed in the cavity of the in-plane surfaceemitting laser.
 54. A fiber optic communication system for transceivinginformation over optical fibers, the fiber optic communication systemincluding: an integrated optically pumped vertical cavity surfaceemitting laser, the integrated optically pumped vertical cavity surfaceemitting laser including, an in-plane semiconductor laser to emitphotons of a relatively short wavelength, the in-plane semiconductorlaser being electrically pumped to generate the photons of therelatively short wavelength; a beam steering element coupled to thein-plane semiconductor laser, the beam steering element to steer thephotons of the relatively short wavelength emitted at an incident anglefrom the in-plane semiconductor laser into a reflective angle; and avertical cavity surface emitting laser coupled to the in-planesemiconductor laser, the vertical cavity surface emitting laser toreceive the photons of the relatively short wavelength emitted from thein-plane semiconductor laser and steered by the beam steering element tobe optically pumped and emit photons of a long wavelength from asurface.
 55. The fiber optic communication system of claim 54 fortransceiving information over optical fibers, wherein, the in-planesemiconductor laser is an edge emitting laser and the beam steeringelement is external to the laser cavity of the edge emitting laser andcouples to the substrate of the edge emitting laser.
 56. The fiber opticcommunication system of claim 54 for transceiving information overoptical fibers, wherein, the in-plane semiconductor laser is an in-planesurface emitting laser and the beam steering element is coupled to thelaser cavity of the in-plane surface emitting laser by being integrallyformed therein.
 57. The fiber optic communication system of claim 54 fortransceiving information over optical fibers, wherein, the integratedoptically pumped vertical cavity surface emitting laser is modulated togenerate a signal by modulating the in plane semiconductor laser. 58.The fiber optic communication system of claim 54 for transceivinginformation over optical fibers, wherein, the integrated opticallypumped vertical cavity surface emitting laser is modulated to generate asignal by an external modulator.
 59. A laser array comprising: aplurality of integrated optically pumped vertical cavity surfaceemitting lasers, each integrated optically pumped vertical cavitysurface emitting lasers including, a folded cavity surface emittinglaser to emit photons of a relatively short wavelength, the foldedcavity surface emitting laser being electrically pumped to generate thephotons of the relatively short wavelength; a beam steering elementcoupled to the folded cavity surface emitting laser, the beam steeringelement to steer the photons of the relatively short wavelength emittedat an incident angle from the folded cavity surface emitting laser intoa reflective angle; and a vertical cavity surface emitting laser coupledto the folded cavity surface semiconductor laser, the vertical cavitysurface emitting laser to receive the photons of the relatively shortwavelength emitted from the folded cavity surface emitting laser andsteered by the beam steering element to be optically pumped and emitphotons of a long wavelength from a surface.
 60. The laser array ofclaim 59, wherein, each of the plurality of integrated optically pumpedvertical cavity surface emitting lasers is separately controlled by aseparate electrical connection to each of the folded cavity surfaceemitting lasers.
 61. The laser array of claim 59, wherein, the pluralityof integrated optically pumped vertical cavity surface emitting lasersare collectively controlled by an electrical connection to each of thefolded cavity surface emitting lasers.
 62. The laser array of claim 59,wherein, each of the plurality of integrated optically pumped verticalcavity surface emitting lasers collectively share a substrate and aportion of a first diffractive Bragg reflector for the folded cavitysurface emitting lasers.
 63. The laser array of claim 59, wherein, eachof the plurality of integrated optically pumped vertical cavity surfaceemitting lasers has a separate portion of a first diffractive Braggreflector, a separate active region, a separate cladding layer includinga separate oxide ridge therein for each folded cavity surface emittinglaser.